/* Handle SVR4 shared libraries for GDB, the GNU Debugger.
Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000,
- 2001, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+ 2001, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 51 Franklin Street, Fifth Floor,
- Boston, MA 02110-1301, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "bfd-target.h"
#include "elf-bfd.h"
#include "exec.h"
+#include "auxv.h"
static struct link_map_offsets *svr4_fetch_link_map_offsets (void);
static int svr4_have_link_map_offsets (void);
-/* This hook is set to a function that provides native link map
- offsets if the code in solib-legacy.c is linked in. */
-struct link_map_offsets *(*legacy_svr4_fetch_link_map_offsets_hook) (void);
-
/* Link map info to include in an allocated so_list entry */
struct lm_info
int arch_size, step, sect_size;
long dyn_tag;
CORE_ADDR dyn_ptr, dyn_addr;
- gdb_byte *bufend, *buf;
+ gdb_byte *bufend, *bufstart, *buf;
Elf32_External_Dyn *x_dynp_32;
Elf64_External_Dyn *x_dynp_64;
struct bfd_section *sect;
return 0;
dyn_addr = bfd_section_vma (abfd, sect);
- /* Read in .dynamic section, silently ignore errors. */
+ /* Read in .dynamic from the BFD. We will get the actual value
+ from memory later. */
sect_size = bfd_section_size (abfd, sect);
- buf = alloca (sect_size);
- if (target_read_memory (dyn_addr, buf, sect_size))
- {
- /* If target_read_memory fails, try reading the BFD file. */
- if (!bfd_get_section_contents (abfd, sect,
- buf, 0, sect_size))
- return 0;
- }
+ buf = bufstart = alloca (sect_size);
+ if (!bfd_get_section_contents (abfd, sect,
+ buf, 0, sect_size))
+ return 0;
/* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
step = (arch_size == 32) ? sizeof (Elf32_External_Dyn)
dyn_tag = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp_32->d_tag);
dyn_ptr = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp_32->d_un.d_ptr);
}
- else
+ else
{
x_dynp_64 = (Elf64_External_Dyn *) buf;
dyn_tag = bfd_h_get_64 (abfd, (bfd_byte *) x_dynp_64->d_tag);
return 0;
if (dyn_tag == dyntag)
{
+ /* If requested, try to read the runtime value of this .dynamic
+ entry. */
if (ptr)
- *ptr = dyn_ptr;
- return 1;
+ {
+ gdb_byte ptr_buf[8];
+ CORE_ADDR ptr_addr;
+
+ ptr_addr = dyn_addr + (buf - bufstart) + arch_size / 8;
+ if (target_read_memory (ptr_addr, ptr_buf, arch_size / 8) == 0)
+ dyn_ptr = extract_typed_address (ptr_buf,
+ builtin_type_void_data_ptr);
+ *ptr = dyn_ptr;
+ }
+ return 1;
}
}
struct minimal_symbol *msymbol;
CORE_ADDR dyn_ptr;
- /* Find DT_DEBUG. */
- if (scan_dyntag (DT_DEBUG, exec_bfd, &dyn_ptr))
- return dyn_ptr;
-
- /* Find DT_MIPS_RLD_MAP. */
+ /* Look for DT_MIPS_RLD_MAP first. MIPS executables use this
+ instead of DT_DEBUG, although they sometimes contain an unused
+ DT_DEBUG. */
if (scan_dyntag (DT_MIPS_RLD_MAP, exec_bfd, &dyn_ptr))
{
gdb_byte *pbuf;
return extract_typed_address (pbuf, builtin_type_void_data_ptr);
}
+ /* Find DT_DEBUG. */
+ if (scan_dyntag (DT_DEBUG, exec_bfd, &dyn_ptr))
+ return dyn_ptr;
+
/* This may be a static executable. Look for the symbol
conventionally named _r_debug, as a last resort. */
msymbol = lookup_minimal_symbol ("_r_debug", NULL, symfile_objfile);
/* Now fetch the filename from target memory. */
target_read_string (l_name, &filename, SO_NAME_MAX_PATH_SIZE - 1, &errcode);
+ make_cleanup (xfree, filename);
if (errcode)
{
return 0;
}
- make_cleanup (xfree, filename);
/* Have a pathname: read the symbol file. */
symbol_file_add_main (filename, from_tty);
{
strncpy (new->so_name, buffer, SO_NAME_MAX_PATH_SIZE - 1);
new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
- xfree (buffer);
strcpy (new->so_original_name, new->so_name);
}
+ xfree (buffer);
/* If this entry has no name, or its name matches the name
for the main executable, don't include it in the list. */
char *buf;
CORE_ADDR load_addr = 0;
int load_addr_found = 0;
+ int loader_found_in_list = 0;
struct so_list *so;
bfd *tmp_bfd = NULL;
struct target_ops *tmp_bfd_target;
be trivial on GNU/Linux). Therefore, we have to try an alternate
mechanism to find the dynamic linker's base address. */
- /* TODO drow/2006-09-12: This is somewhat fragile, because it
- relies on read_pc. On both Solaris and GNU/Linux we can use
- the AT_BASE auxilliary entry, which GDB now knows how to
- access, to find the base address. */
-
tmp_fd = solib_open (buf, &tmp_pathname);
if (tmp_fd >= 0)
tmp_bfd = bfd_fopen (tmp_pathname, gnutarget, FOPEN_RB, tmp_fd);
if (strcmp (buf, so->so_original_name) == 0)
{
load_addr_found = 1;
+ loader_found_in_list = 1;
load_addr = LM_ADDR_CHECK (so, tmp_bfd);
break;
}
so = so->next;
}
+ /* If we were not able to find the base address of the loader
+ from our so_list, then try using the AT_BASE auxilliary entry. */
+ if (!load_addr_found)
+ if (target_auxv_search (¤t_target, AT_BASE, &load_addr) > 0)
+ load_addr_found = 1;
+
/* Otherwise we find the dynamic linker's base address by examining
the current pc (which should point at the entry point for the
- dynamic linker) and subtracting the offset of the entry point. */
+ dynamic linker) and subtracting the offset of the entry point.
+
+ This is more fragile than the previous approaches, but is a good
+ fallback method because it has actually been working well in
+ most cases. */
if (!load_addr_found)
+ load_addr = (read_pc ()
+ - exec_entry_point (tmp_bfd, tmp_bfd_target));
+
+ if (!loader_found_in_list)
{
- load_addr = (read_pc ()
- - exec_entry_point (tmp_bfd, tmp_bfd_target));
debug_loader_name = xstrdup (buf);
debug_loader_offset_p = 1;
debug_loader_offset = load_addr;
/* For whatever reason we couldn't set a breakpoint in the dynamic
linker. Warn and drop into the old code. */
bkpt_at_symbol:
+ xfree (tmp_pathname);
warning (_("Unable to find dynamic linker breakpoint function.\n"
"GDB will be unable to debug shared library initializers\n"
"and track explicitly loaded dynamic code."));
struct solib_svr4_ops *ops;
ops = OBSTACK_ZALLOC (obstack, struct solib_svr4_ops);
- ops->fetch_link_map_offsets = legacy_svr4_fetch_link_map_offsets_hook;
+ ops->fetch_link_map_offsets = NULL;
return ops;
}
/* Set the architecture-specific `struct link_map_offsets' fetcher for
- GDBARCH to FLMO. */
+ GDBARCH to FLMO. Also, install SVR4 solib_ops into GDBARCH. */
void
set_solib_svr4_fetch_link_map_offsets (struct gdbarch *gdbarch,
struct solib_svr4_ops *ops = gdbarch_data (gdbarch, solib_svr4_data);
ops->fetch_link_map_offsets = flmo;
+
+ set_solib_ops (gdbarch, &svr4_so_ops);
}
/* Fetch a link_map_offsets structure using the architecture-specific
|| scan_dyntag (DT_SYMBOLIC, objfile->obfd, NULL) != 1)
return NULL;
- return lookup_global_symbol_from_objfile
+ return lookup_global_symbol_from_objfile
(objfile, name, linkage_name, domain, symtab);
}
+static int
+svr4_same (struct so_list *gdb, struct so_list *inferior)
+{
+ if (! strcmp (gdb->so_original_name, inferior->so_original_name))
+ return 1;
+
+ /* On Solaris, when starting inferior we think that dynamic linker is
+ /usr/lib/ld.so.1, but later on, the table of loaded shared libraries
+ contains /lib/ld.so.1. Sometimes one file is a link to another, but
+ sometimes they have identical content, but are not linked to each
+ other. We don't restrict this check for Solaris, but the chances
+ of running into this situation elsewhere are very low. */
+ if (strcmp (gdb->so_original_name, "/usr/lib/ld.so.1") == 0
+ && strcmp (inferior->so_original_name, "/lib/ld.so.1") == 0)
+ return 1;
+
+ return 0;
+}
+
extern initialize_file_ftype _initialize_svr4_solib; /* -Wmissing-prototypes */
void
svr4_so_ops.open_symbol_file_object = open_symbol_file_object;
svr4_so_ops.in_dynsym_resolve_code = svr4_in_dynsym_resolve_code;
svr4_so_ops.lookup_lib_global_symbol = elf_lookup_lib_symbol;
-
- /* FIXME: Don't do this here. *_gdbarch_init() should set so_ops. */
- current_target_so_ops = &svr4_so_ops;
+ svr4_so_ops.same = svr4_same;
}